CMB, The Horizon Problem and a comment on BH's

[bapowell]

Excellent. Thanks for going through this all with me. I'm happy to say the horizon problem makes sense.

Great! Happy to help.

Additionally I never realized that non-infamitory models required a constant rate of expansion of the scale factor, which makes sense also.

I hope I didn't say this! By definition, non-inflationary spacetimes need only satisfy $\ddot{a}<0$. The scale factor in non-inflationary models is not necessarily constant -- for example, in a radiation dominated universe $a(t) \sim t^{1/2}$, whereas in a matter dominated one $a(t) \sim t^{2/3}$.

 

[superg33k]

I hope I didn't say this!

Yep, your right, you didn't. An inequality became an equality in my head.